U.S. patent application number 17/492412 was filed with the patent office on 2022-04-07 for apparatus, systems, and methods for generating force in electromagnetic systems.
The applicant listed for this patent is Gary C. Berkowitz, Thomas Alexander Johnson. Invention is credited to Gary C. Berkowitz, Thomas Alexander Johnson.
Application Number | 20220109361 17/492412 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-07 |
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United States Patent
Application |
20220109361 |
Kind Code |
A1 |
Johnson; Thomas Alexander ;
et al. |
April 7, 2022 |
APPARATUS, SYSTEMS, AND METHODS FOR GENERATING FORCE IN
ELECTROMAGNETIC SYSTEMS
Abstract
Apparatus, systems, and methods used to produce linear and
rotational motion, acceleration, and actuation by the use of mobile
ferromagnetic or permanent magnets subjected to asymmetric
electromagnetic field distributions are disclosed herein. A variety
of exemplary embodiments and applications are described, involving
different coil and actuator geometries to include and allow for
both stationary and moving magnets, electric fields, and magnetic
fields.
Inventors: |
Johnson; Thomas Alexander;
(Evergreen, CO) ; Berkowitz; Gary C.; (Centennial,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Johnson; Thomas Alexander
Berkowitz; Gary C. |
Evergreen
Centennial |
CO
CO |
US
US |
|
|
Appl. No.: |
17/492412 |
Filed: |
October 1, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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63086737 |
Oct 2, 2020 |
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International
Class: |
H02K 41/035 20060101
H02K041/035; H02K 33/18 20060101 H02K033/18 |
Claims
1. A linear actuator comprising: a plunger; one or more first coil
members circumscribing a central axis, wherein the one or more
first coil members are configured to produce a first asymmetrical
field distribution having a greater flux density at a first end of
the linear actuator; and one or more second coil members
circumscribing the central axis, wherein the one or more second
coil members are configured to produce a second asymmetrical field
distribution having a greater flux density at a second opposing end
of the linear actuator; wherein the one or more first coil members
and the one or more second coil members are further configured such
that the each of first asymmetrical flux density and the second
asymmetrical flux density is independently controllable to cause
motion of the plunger along the central axis relative to the one or
more first coil members and the one or more second coil
members.
2. The linear actuator of claim 1, wherein the one or more first
coil members comprises a first coil on a first circuit, the first
coil comprising two or more sections of first windings, each of the
two or more sections of first windings at least partially radially
overlapping with an adjacent section of first windings, the two or
more sections of first windings configured such that there is a
greater number of overlapping first windings distributed toward the
first end of the linear actuator relative to a center of the linear
actuator.
3. The linear actuator of claim 1, wherein the one or more second
coil members comprises a second coil on a second circuit, the
second coil comprising two or more sections of second windings,
each of the two or more sections of second windings at least
partially radially overlapping with an adjacent section of second
windings, the two or more sections of second windings configured
such that there is a greater number of overlapping second windings
distributed toward the second opposing end of the linear actuator
relative to a center of the linear actuator.
4. The linear actuator of claim 1, wherein the one or more first
coil members comprises a plurality of first coil members each on a
separate circuit, wherein each first coil member comprises a
portion of first windings that radially overlaps with an adjacent
first coil member, the plurality of first coil members configured
such that there is a greater number of overlapping first windings
distributed toward the first end of the linear actuator relative to
a center of the linear actuator.
5. The linear actuator of claim 1, wherein the one or more second
coil members comprises a plurality of second coil members each on a
separate circuit, wherein each second coil member comprises a
portion of second windings that radially overlaps with an adjacent
second coil member, the plurality of second coil members configured
such that there is a greater number of overlapping second windings
distributed toward the second opposing end of the linear actuator
relative to a center of the linear actuator.
6. The linear actuator of claim 1, wherein the one or more first
coil members and the one or more second coil members are further
configured such that the each of first asymmetrical flux density
and the second asymmetrical flux density are independently
controllable to stop motion of the plunger along the central axis
relative to the one or more first coil members and the one or more
second coil members.
7. The linear actuator of claim 1, further comprising a first
variable power source in communication with the one or more first
coil members, and a second variable power source in communication
with the one or more second coil members.
8. The linear actuator of claim 1, wherein the linear actuator is
configured for communication with a controller, the controller in
communication with and configured to control power from a first
variable power source to the one or more first coil members for
production of the first asymmetrical field density and control
power from a second variable power source to the one or more second
coil members for production of the second asymmetrical field
density.
9. The linear actuator of claim 1, wherein the linear actuator is
configured to be controlled such that, when more power is applied
to the one or more first coil members relative to the one or more
second coil members, the first asymmetrical flux density acts on
the plunger to result in at least one of movement of the plunger
toward the first end of the linear actuator or retarding movement
of the plunger toward the second opposing end of the linear
actuator.
10. The linear actuator of claim 1, wherein the linear actuator is
configured to be controlled such that, when more power is applied
to the one or more second coils relative to the one or more first
coils, the second asymmetrical flux density acts on the plunger to
result in at least one of movement of the plunger toward the second
opposing end of the linear actuator or retarding of movement of the
plunger toward the first end of the linear actuator.
11. The linear actuator of claim 1, wherein the linear actuator is
configured to be controlled such that, controlling a ratio of flux
density of the first asymmetrical flux density relative to the
second asymmetrical flux density results in control of one or more
of a speed of the plunger moving along the central axis, a position
of the plunger on the central axis, a direction of movement of the
plunger along the central axis, or a stroke length of the plunger
along the central axis.
12. A linear actuator comprising: one or more first coil members
circumscribing a central axis; and a plunger disposed at least
partially within the one or more first coil members; wherein the
one or more first coil members are configured to produce a first
asymmetrical field distribution having a first peak density toward
a first end of the linear actuator; and wherein the first
asymmetrical field distribution is configured to have an increased
maximum stroke length of the plunger along the central axis
relative to a coil having symmetrical field density and a same
length as the one or more first coil members.
13. The linear actuator of claim 12, wherein the one or more first
coil members comprises a plurality of first coil members each on a
separate circuit, wherein each first coil member comprises a
portion of first windings that radially overlaps with an adjacent
first coil member, the plurality of first coil members configured
such that there is a greater number of overlapping first windings
distributed toward the first end of the linear actuator.
14. The linear actuator of claim 13, wherein the linear actuator is
configured such that a polarity of each of the one or more first
coil members is independently controllable relative to others of
the one or more first coil members.
15. The linear actuator of claim 12, further comprising one or more
second coils members circumscribing the central axis, the one or
more second coil members arranged to have a greater coil density at
the second opposing end of the linear actuator relative to a center
of the linear actuator, wherein the one or more second coil members
are configured to produce a second asymmetrical field distribution
having a second peak density toward the second opposing end of the
linear actuator.
16. The linear actuator of claim 15, wherein the linear actuator is
configured for communication with a controller, the controller
configured to control a ratio of flux density between the first
asymmetrical field distribution and the second asymmetrical field
distribution to control one or more of a speed of the plunger
moving along the central axis, a position of the plunger on the
central axis, a direction of movement of the plunger along the
central axis, or a stroke length of the plunger along the central
axis.
17. A linear actuator comprising: a plunger; one or more first coil
members circumscribing a central axis and comprising a greater
number of overlapping windings at a first end of the linear
actuator relative to a center of the linear actuator, wherein the
one or more first coil members are configured to generate a first
asymmetrical field distribution having a greater flux density at
the first end of the linear actuator; a first variable power source
in communication with at least one of the one or more first coil
members; one or more second coil members circumscribing the central
axis and comprising a greater number of overlapping windings at a
second opposing end of the linear actuator relative to the center
of the liner actuator, wherein the one or more second coil members
are configured to generate a second asymmetrical field distribution
having a greater flux density at the second opposing end of the
linear actuator; and a second variable power source in
communication with at least one of the one or more first coil
members; wherein the one or more first coil members and the one or
more second coil members are further configured such that one or
more of a speed of the plunger moving along the central axis, a
position of the plunger on the central axis, a direction of
movement of the plunger along the central axis, or a stroke length
of the plunger along the central axis is controlled via a ratio of
flux density between the first asymmetrical field distribution and
the second asymmetrical field distribution.
18. The linear actuator of claim 17, wherein the linear actuator is
configured for communication with a controller, the controller in
communication with and configured to control power from the first
variable power source to the one or more first coil members for
production of the first asymmetrical field density and control
power from the second variable power source to the one or more
second coil members for production of the second asymmetrical field
density.
19. The linear actuator of claim 17, wherein the plunger comprises
two or more plunger segments each connected to an adjacent plunger
segment by a connection member.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 63/086,737, filed on Oct. 2, 2020, which is
incorporated herein by reference in its entirety.
FIELD
[0002] The present disclosure is generally directed to
electromagnetic machines, and more specifically to electromagnetic
actuators.
BACKGROUND
[0003] In a general electromagnetic force-generating system, a
current-carrying conductor, which by Oersted's Law generates a
magnetic field (given by Biot-Savart), interacts with an external
magnetic field, and thus, a force on both the conductor and a
source of the external magnetic field is generated. According to
well established laws of electrodynamics, this interaction, when
asymmetric, produces motion.
[0004] For example, in a common solenoid device (such as the
solenoid device illustrated in and discussed below with reference
to FIGS. 1A and 1B), a rigid magnetic or ferromagnetic
(non-permanent) object, commonly termed a plunger or a core (or
sometimes, an armature, not to be confused with the use of armature
in electrical technology, meaning a framework of coil windings), is
suspended near or partly within a cylindrical current-carrying
solenoid (which may also be referred to as a coil). The application
of current in the coil generates a magnetic force that propels the
object along the axis of the coil, always in such a manner as to
pull the plunger toward the midpoint of the coil. In this example,
the force that is experienced by the plunger is dependent on the
position of the plunger along the axis of the solenoid magnetic
field. The maximum force on the plunger occurs when one end of the
plunger is at the endpoint of the coil (FIG. 1A). The equilibrium
point of zero net force occurs when the midpoint of the plunger
aligns with the midpoint of the coil (FIG. 1B). This is because,
when at the midpoint of the coil, equal and opposite magnetic
forces act on the N and S ends of the plunger concurrently. When a
non-magnetic extension of the plunger is used to cause an action to
take place outside the end of solenoid, the system is commonly
referred to as a proportional, axial, or linear actuator. The range
of motion, with a maximum range of motion being one-half the length
of the plunger, defines a stroke of the solenoid linear
actuator.
[0005] In existing solenoid linear actuators, the net magnetic
force that acts on the object (plunger) in motion, typically a
ferromagnetic rod or a permanent magnet, is generally linear along
the entire stroke except at the opposing ends of the coil. Thus, as
noted above, the maximum stroke is limited to half the coil length.
However, linear forces are not always ideal in linear actuator
applications. Thus, there is a continuing need for improved linear
actuators, including those configured to provide nonlinear forces,
and especially those configured for a longer stroke for the same
coil length.
SUMMARY
[0006] Disclosed herein are apparatus and methods for generating
nonlinear force in electromagnetic actuator systems. The apparatus
and methods disclosed herein are configured with one or more coils
arranged to provide a nonuniform (asymmetric) field distribution,
yielding a longer stroke than previously achievable with known
solenoid linear actuators. In some embodiments, the disclosed
apparatus and methods are directed to linear actuators. In some of
those embodiments, the linear actuators are configured to provide
nonlinear acceleration.
[0007] Such linear actuators (as those described herein) can be
used in various applications. For example, the disclosed technology
can be used for high-performance, long-stroke linear, and/or
rotational actuators. The disclosed linear actuators can also be
used, for example, when an application involves either crushing or
stretching a target. Often, the forces on the object may be better
suited if they are not linear in these cases, as the force required
to crush or stretch an object changes over the length of the stroke
(i.e., the required force is nonlinear). As yet another example, it
may be advantageous to have nonlinear acceleration in situations
where the smooth transition of speed of the object in motion is
desired, such as in accelerating a passenger train or a car.
[0008] As a general overview of the disclosed linear actuators, a
ferromagnetic object, after being inserted axially into a
current-carrying coil, will experience a force, which projects the
ferromagnetic object toward the center of the coil where the forces
on the moving ferromagnetic object from each of the poles find
equilibrium. It will be appreciated that shorter coils possess a
shorter distance to the midpoint than do larger coils, so the
stroke is shorter in a shorter coil relative to a larger coil. To
increase the stroke without increasing the length of a coil, we add
a slightly shorter secondary winding on the outside and towards one
end of a primary coil (as illustrated in and discussed below with
reference to FIG. 2A). Now a ferromagnetic object can be moved to a
slightly displaced position from the center of the coil as the
object is brought to equilibrium within the two coils acting on it.
The ferromagnetic object therefore can be displaced past the center
of the coil, toward the end with the secondary winding. As shorter
and shorter coils of increasing radius are added to the periphery
of a solenoid, and displaced or offset toward one end thereof, the
equilibrium point can be displaced further towards one pole of the
innermost solenoid coil (as illustrated in and discussed below with
reference to FIG. 2B). There may be a limit to how close the
equilibrium and/or the ferromagnetic object can move or shift
toward one pole. The objective, however, can be that an object
using this system attains the advantage of a much longer range of
actuation as compared to known solenoid coil winding geometry.
[0009] One exemplary objective of the linear actuators disclosed
herein is to generate a longer stroke than previously achievable
with a single-coil solenoid actuator of the same length. In effect,
the asymmetric layered-coil geometry can create a non-linear
magnetic field density along the solenoid, which preponderates
towards one end thereof, thus enabling a wider range of motion.
Using this kind of system, it may be possible for a magnetic object
in motion in a linear actuator to experience a force that propels
the magnetic object along the nearly entire length of the coil
before it reaches the point at which opposing forces begin to bring
the magnetic object to rest (equilibrium). Using multiple coils
with differing levels of current such that the force preponderates
from one coil to the next can be an alternative way of achieving
this effect (as illustrated in and discussed below with reference
to FIGS. 3A and 3B). Whichever embodiment the invention takes, so
long as the magnetic field distribution is nonuniform, the length
of the stroke can be increased over that of a comparable coil
possessing a uniform magnetic field distribution. It is
advantageous for there to be mechanical stops in the actuator to
stop the plunger from going past the limits of the plunger's
stroke, so as to always be able to reverse the polarity supplied to
the solenoid, thereby reversing the direction of forces on a
plunger, which may have been, for example, a permanent magnet that
is magnetized throughout its length.
[0010] These and other features, aspects, and/or advantages of the
present disclosure will become better understood with reference to
the following detailed description and the claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the disclosed technology
and, together with the description, explain the principles of the
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1A and 1B are schematic diagrams of a known solenoid
with a single coil and a ferromagnetic plunger in a maximum-force
configuration and a zero net force configuration.
[0012] FIGS. 2A and 2B are schematic diagrams of one exemplary
embodiment of a linear actuator including a solenoid with a
plurality of layered coils displaced toward one end of a primary
coil, in accordance with the present disclosure.
[0013] FIGS. 3A and 3B are schematic diagrams of another exemplary
embodiment of a linear actuator including a plurality of separate
coils arranged in a linear configuration, in accordance with the
present disclosure.
[0014] FIGS. 4A and 4B are schematic diagrams of another exemplary
embodiment of a linear actuator, wherein the use of nonuniform
electric fields generates asymmetric electromagnetic forces that
tend to attract the actuating plunger towards the point of highest
electric potential, in accordance with the present disclosure.
[0015] FIGS. 5A-5C are schematic diagrams of another exemplary
embodiment of a linear actuator, wherein the field distribution
gradient takes place along a curved route, so as to create a
rotational actuator, in accordance with the present disclosure.
[0016] FIG. 6 is a schematic diagram of another exemplary
embodiment of a linear actuator, wherein a plurality of separate
coils with differing turn counts are used to create the
asymmetrical magnetic flux density, in accordance with the present
disclosure.
[0017] FIGS. 7A and 7B are schematic diagrams of another exemplary
embodiment of a linear actuator, wherein concatenated permanent
magnets of increasing field strength are utilized to produce an
asymmetrical flux density, and a coil configured to, with electric
current applied thereto, produce motion of either the permanent
magnets or the coil itself, in accordance with the present
disclosure.
[0018] FIGS. 8A and 8B are schematic diagrams of another exemplary
embodiment of a linear actuator, wherein two sets of coil
geometries are arranged on opposite ends of the actuator axis, each
set connected to a separate a voltage source and potentiometer,
which is configured to create a push-pull effect, and a maximally
variable axial profile of the magnetic flux density, in accordance
with the present disclosure.
[0019] FIG. 9 is a schematic diagram of an exemplary plunger
configured for use the exemplary actuator of FIGS. 8A and 8B.
[0020] FIG. 10 is a schematic diagram of an exemplary coil core
that can be utilized in combination with the exemplary actuators
disclosed herein.
[0021] FIG. 11 is a schematic diagram of another exemplary
embodiment of a linear actuator, in accordance with the present
disclosure.
[0022] FIG. 12 is an exemplary curve illustrating distance by the
inverse square function for the actuators disclosed herein.
[0023] FIG. 13 is a schematic diagram of showing acceleration of
ionized particles over a wider length due to a nonhomogeneous
electric field, in accordance with the present disclosure.
[0024] FIG. 14 is a logical block diagram of an exemplary actuator
and controller system, in accordance with the present
disclosure.
DETAILED DESCRIPTION
General Considerations
[0025] The systems and methods described herein, and individual
components thereof, should not be construed as being limited to the
particular uses or systems described herein in any way. Instead,
this disclosure is directed toward all novel and non-obvious
features and aspects of the various disclosed embodiments, alone
and in various combinations and subcombinations with one another.
For example, any features or aspects of the disclosed embodiments
can be used in various combinations and subcombinations with one
another, as will be recognized by an ordinarily skilled artisan in
the relevant field(s) in view of the information disclosed herein.
In addition, the disclosed systems, methods, and components thereof
are not limited to any specific aspect or feature or combinations
thereof, nor do the disclosed things and methods require that any
one or more specific advantages be present or problems be
solved.
[0026] As used in this application, the singular forms "a," "an,"
and "the" include the plural forms unless the context clearly
dictates otherwise. Additionally, the term "includes" means
"comprises." Further, the terms "coupled" or "secured" encompass
mechanical and chemical couplings, as well as other practical ways
of coupling or linking items together, and do not exclude the
presence of intermediate elements between the coupled items unless
otherwise indicated, such as by referring to elements, or surfaces
thereof, being "directly" coupled or secured. Furthermore, as used
herein, the term "and/or" means any one item or combination of
items in the phrase.
[0027] As used herein, the term "exemplary" means serving as a
non-limiting example, instance, or illustration. As used herein,
the terms "e.g.," and "for example," introduce a list of one or
more non-limiting embodiments, examples, instances, and/or
illustrations.
[0028] As used herein, the terms "non-linear" and "nonhomogeneous"
are generally used to describe the irregular shape of the electric
or magnetic flux lines when they are produced in a way that varies
in intensity from one end of the source of the field to the
other.
[0029] Although the operations of some of the disclosed methods are
described in a particular, sequential order for convenient
presentation, this manner of description encompasses rearrangement,
unless a particular ordering is required by specific language set
forth below. For example, operations described sequentially may in
some cases be rearranged or performed concurrently. Moreover, for
the sake of simplicity, the attached figures may not depict the
various ways in which the disclosed things and methods can be used
in conjunction with other things and methods. Additionally, the
description sometimes uses terms like "provide" and "produce" to
describe the disclosed methods. These terms are high-level
descriptions of the actual operations that are performed. The
actual operations that correspond to these terms will vary
depending on the particular implementation and are readily
discernible by one of ordinary skill in the art having the benefit
of this disclosure.
[0030] As used herein, the terms "attached" and "coupled" generally
mean physically connected or linked, which includes items that are
directly attached/coupled and items that are attached/coupled with
intermediate elements between the attached/coupled items, unless
specifically stated to the contrary.
[0031] As used herein, the terms "solenoid coil", "solenoid, and
"coil" generally refer to the coil winding part of the linear
actuator. The term "solenoid actuator" generally refers to the
entire actuator as a whole and can distinguish from other forms of
linear actuators such as hydraulic, motorized, and pneumatic
actuators.
[0032] As used herein, the terms "fixedly attached" and "fixedly
coupled" refer to two components joined in a manner such that the
components may not be readily separated from one another without
destroying and/or damaging one or both components. Exemplary
modalities of fixed attachment may include joining with permanent
adhesive, stitches, welding or other thermal bonding, and/or other
joining techniques. In addition, two components may be "fixedly
attached" or "fixedly coupled" by virtue of being integrally
formed, for example, in a molding process. In contrast, the terms
"removably attached" or "removably coupled" refer to two components
joined in a manner such that the components can be readily
separated from one another to return to their separate, discrete
forms without destroying and/or damaging either component.
Exemplary modalities of temporary attachment may include
mating-type connections, releasable fasteners, removable stitches,
and/or other temporary joining techniques.
[0033] Unless explained otherwise, all technical and scientific
terms used herein have the same meaning as commonly understood to
one of ordinary skill in the art to which this disclosure belongs.
Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of the
present disclosure, suitable methods and materials are described
below. The materials, methods, and examples are illustrative only
and not intended to be limiting. Other features of the disclosure
are apparent from the detailed description, abstract, and
drawings.
Exemplary Embodiments
[0034] For reference, FIGS. 1A and 1B depict an example of a known
solenoid or linear actuator 100. As illustrated therein, the linear
actuator 100 includes a coil 101 and a plunger 108, which is a
magnet or a magnetized object magnetized through its length with
the North Pole 109 of the plunger 108 aiming away from the North
Pole 106 of the solenoid. In this position, the plunger 108
experiences a net force 112, which can pull the plunger 108 into
the coil 101 due to the magnetic force 105 generated by the current
source 103. The direction of the current flow 104 through a circuit
102 and through the windings of the coil 101 determine the polarity
of the coil (i.e., the orientation of the North Pole 106 and the
South Pole 107). In this case, the plunger 108 is resting within
the first turn 111 of the windings of the coil 101. A winding 104a
overlaps with another part of the coil in order to illustrate the
winding direction of the coil 101. The switch 116 is depicted in
the open position 116a to show that there is no current flow
through the coil. The mid-point 110 of the plunger 108 is in a
position that allows for a force 112 to be exerted upon the plunger
when current is flowing.
[0035] As discussed above, the shutting of the switch 117 allows
for the flow of current to enter the coil 101 which generates a
magnetic force that propels the plunger 108 along the axis of the
coil, such that the plunger is pulled toward the midpoint of the
coil 108. In this example, the force 112 that is experienced by the
plunger 108 is dependent on the position of the plunger along the
axis of the solenoid's magnetic field. The maximum force on the
plunger 108 occurs when one end of the plunger is at the endpoint
of the coil 101 (as illustrated in FIG. 1A). The equilibrium point
of zero net force occurs when the midpoint 110 of the plunger 108
aligns with the midpoint of the coil 101 (as illustrated in FIG.
1B). This is because, when at the midpoint of the coil 101, equal
and opposite magnetic forces act on the N and S ends of the plunger
108 concurrently. A distance 115 corresponds to the stroke of the
solenoid actuator which ends at the center of the coil 113, and is
defined by an original position 110a the center 110 of the plunger
108 and a final position 113 of the center 110 of the plunger 108.
When the plunger is at position 113, the force on the plunger 114
may be very nearly equal to zero.
[0036] One exemplary embodiment of a solenoid linear actuator 200
according the present disclosure is shown in FIGS. 2A and 2B. As
can be seen therein, the solenoid actuator 200 includes a plurality
of coils, which have their windings arranged with a geometry that
can cause the magnetic force to preponderate towards one pole, and
can be configured to act upon a plunger (i.e., magnetized object)
208 along a straight/linear axis of movement. In the present
embodiment, the coil geometry includes more windings or coils
(coils 201, 202, 203) towards one end of the solenoid actuator 200
relative to the opposing end thereof. It will be understood that
the plunger or magnetized object 208 can be a temporary or
permanent magnet, a ferromagnetic material, or another
electromagnetic coil connected to a source of electricity. It will
additionally be understood that the plunger 208 may be positioned
on top of the coils, within the coils, or a combination thereof so
long as it can be acted upon by the nonlinear magnetic field
density to produce a longer stroke of actuation relative to the
conventional linear actuator 100 of FIGS. 1A and 1B, where the peak
magnetic field density is located in the center of the coil 101
(i.e., at the center of the coil's bounds).
[0037] In some embodiments, an elastic band or spring secured to
the magnetized object 208 may also be used to create an additional
source of force on the plunger 208 in instances or conditions where
it is deemed advantageous, such as, for example, in instances in
which more linear forces across the stroke are desired. In another
example, an additional source of force or tension can allow for the
plunger 208 to return to a starting position after it is moved the
full stroke of motion if the power is subsequently turned off. This
can be advantageous if, for example, an application requires or
implements a linear actuator that is designed to be connected to a
DC source with no option of reversing the polarity, as this can
allow for the plunger in the system to undergo forward movements
(due to the magnetic field when the power is turned off) and
backward movements (due to the tension acting in the opposing
direction when the power is turned off). Furthermore, such
embodiments can be advantageous when a variable power source is
used in order to overcome the tension partially but not completely,
thereby enabling control or alteration the plunger's position along
the solenoid coil.
[0038] Returning to FIG. 2A, the plunger 208 in the solenoid
actuator 100 possesses an asymmetrical magnetic flux density
(illustrated by a tapering B-field 207). In this case, the plunger
208 is oriented such that the north pole 209 thereof is facing the
opposite direction of the coil (i.e., facing away from the coil).
The windings of the coil 201 span from one end (a first end) of the
linear actuator 100 to the opposing (second) end of the actuator.
At the opposing end, the coil 201 can be connected to where it
connects to windings of a second coil 202 via a first connecting
wire 201a. The second coil 202 then connects to windings of a third
coil 203 via a second connecting wire 202a. The windings of the
second coil 202 can be wrapped over a portion of the windings of
the first coil 201 so as to produce a magnetic field density that
preponderates towards one end (e.g., the right side) of the
solenoid actuator 200. The third coil 203 is wrapped over a portion
of the windings of the second coil 202 so as to produce a magnetic
field density that further preponderates toward one end (e.g., the
right side) of the solenoid actuator 200. FIG. 2A specifically
illustrates a moment when a switch 219 on an electrical circuit is
moving from an open position 216 towards closing, causing current
204 to flow into the solenoid actuator 200 in a specified direction
205. A winding 203a overlaps with another part of the coil in order
to illustrate the winding direction of the coil 201.
[0039] FIG. 2B illustrates the solenoid actuator 200 after the
switch 219 has been moved into a closed position 217. When the
switch 219 is in the closed position 217, the plunger 208 moved a
stroke of distance 215, which is greater that a stroke distance 115
of the solenoid actuator 100 depicted in FIG. 1B, when the coils
101 and 201 are of equal or similar length. This stroke distance
215 depicted in FIG. 2B illustrates that the midpoint of the
plunger 208 moves from an initial position 210a) to a resting
position 210, which corresponds closely with the peak magnetic flux
density along the coils 201, 202, 203 of the solenoid actuator 200.
The potential B field 207 may be generated or manifested when the
switch 207 is closed.
[0040] When the plunger 208 is held stationary, the coils 201, 202,
203 can experience a force in the solenoid actuator 200 system.
When the polarity of one or more of the coils 201, 202, 203 is
reversed, the forces created by the action of the reversed coil on
the other components in the solenoid actuator can be reversed. The
number of the windings in each respective coil 201, 202, 203 and
the power flow to each coil 201, 202, 203 may determine the
position of the plunger 208 in the solenoid actuator 200.
Therefore, the present embodiment can enable variable or adjustable
position control of the plunger 208 utilizing e.g., a controller
apparatus (such as, the computerized controller apparatus 1410
discussed below with reference to FIG. 14), especially when the
coils are powered separately rather than being joined together in
one circuit (as in the embodiment of FIG. 6, discussed below). The
generated B field 207a produced by the closing of the switch 216b
is shown in FIG. 2B.
[0041] The construction of coils such as those shown in FIG. 2A and
FIG. 2B can be accomplished by altering the graduation in the
number of windings of the coil. A graduation of one layer of
windings may have at least three fewer (-3) windings than the
preceding layer. In other words, the winding count of each
consecutive layer can have at least three fewer turns than the
previous layer. Each consecutive layer can be displaced towards one
end so that the profile of the coil is similar to that shown in
FIG. 2A and FIG. 2B, which is to say that the profile of the
solenoid shows that the most windings are conglomerated at or
distributed toward one end of the solenoid and there are relatively
less on the other end. In alternate embodiments, the coils or
windings can be with separate spools of wire, each with different
turn counts where the higher number of turn counts preponderates
toward one end, and which are electrically connected to the next
spool of wire in such a way that the profile of the windings takes
a form similar to that shown in FIG. 2A and FIG. 2B. The spools of
wire may be spaced with minimum distance between them (for example,
1 mm spacing between the spools of wire). As described above, there
may be a minimum difference of three turns of windings between each
adjacent spool of wire.
[0042] It will be appreciated the applying asymmetrical flux
density to a linear actuator can enable prediction or control of
the plunger's stopping point based on the number of windings in the
coils and/or the power flow through their respective circuits. For
example, the force on the plunger along the stroke of the solenoid
actuator and/or the stopping position of the plunger can be
calculated using mathematical analysis allowing further
predictability and refinement as one or more parameters in the
system (such as, e.g., power flow) are altered. Furthermore, the
apparatus and methods disclosed herein for supplying power to a
solenoid actuator with variable position control (via controlling
differences in the power of the branches of the circuit and the
polarity of the coils acting on the plunger) allow for or enable an
operator or a control board to perform actions that previously
(utilizing convention solenoid actuators) would have required
rather complicated controllers including, for example, hydraulic,
pneumatic, and/or 3 phase linear motors. Further, conventions
solenoid actuators are normally only able to perform a single
action (e.g., movement of the plunger in a first direction), and
all subsequent actions (e.g., movement of the plunger in an
opposing second direction) may require a return spring or other
mechanisms to return the plunger to the point of highest force
production. The present embodiment depicts one configuration or
strategy that can enable full electrical control of the position of
the plunger by incorporating an asymmetrical magnetic field density
(such as e.g., the tapering B-field 207 shown in FIG. 2A) along the
stroke of the plunger.
[0043] In some embodiments, an actuator can include a plurality of
overlapping coils that may be turned on or off at will. As such,
the coils can introduce forces to the system in a nonlinear way,
thereby allowing a given apparatus utilizing the actuator to
produce multiple force profiles, each of which may tend to center
an object or plunger in motion in selected locations and may give
rise to different forces acting on the object or plunger. Where a
plurality coils are present and actuated individually, various
profiles for forces may be available, as depicted in FIG. 6 and
discussed below.
[0044] FIG. 6 illustrates another embodiment wherein a solenoid
actuator 600 is comprised of coils of differing turn count and
diameter in order to aid in the production of the magnetic field
asymmetry, which can thereby lengthen the stroke of plunger.
Different from the solenoid actuator 600, each of the coils 601a,
602a, 603a in this embodiment is respectively connected to separate
power sources on separate circuits 601, 602, 603, which each have a
separate power switch 610, 611, 612. The innermost coil 601a
stretches the full length of the solenoid actuator 600 and, when
turned on in isolation, the coil 601a can draw the plunger 608 to
the center point of the coil 601a. A shorter second coil 602a can
be wound over the top of a portion or a section of the first coil
601a so that it is displaced or positioned towards one side or end
(e.g., a right side) of the actuator 600. A third coil 603a is
wound over the second coil 602a and is similarly displaced or
positioned toward one side or end (e.g., a right side) of the
actuator. When Currents I.sub.1, I.sub.2, I.sub.3 can be
respectively applied to each of the coils 601a, 602a, 603a. When
the currents I.sub.1, I.sub.2, I.sub.3 are equal and each circuit
has power flowing through the coils 601a, 602a, 603a, a magnetic
field is generated in a manner that can cause the peak magnetic
field density to be displaced from the center of e.g., the coil
601a toward one end of the solenoid actuator, and therefore the
plunger 608 can be moved to a position that is closer toward the
end of the solenoid actuator relative to a conventional solenoid
actuator (such as e.g., the solenoid actuator 100 shown in FIG. 1).
Further, if the polarity through one or more of the power sources
601, 602, 603 is reversed, the plunger 608 can come to equilibrium
at the opposite end of the solenoid actuator 600.
[0045] In additional or alternate embodiments, a solenoid actuator
or a linear motor configured to generate a nonuniform magnetic
field gradient can include a plurality of co-linear coils fed by
different circuits (such as in the embodiment of FIG. 6), wherein a
positional sensor can allow for the circuits to switch off as the
object passes them so as to reduce a force pulling a plunger in
motion backward. Further, the circuits can be controlled (utilizing
e.g., a controller apparatus such as, the computerized controller
apparatus 1410 discussed below with reference to FIG. 14) to change
their polarity in order to resist a backward movement of the
plunger under circumstances where it is desirable to do so as, for
example, when a weighted object is connected to the plunger and its
position is meant to be held constant. In implementations, the
coils that are changed to an alternate polarity can be those that
are not immediately neighboring the coils that are still acting on
the plunger as to limit destructive interference in their
respective magnetic fields.
[0046] In another exemplary embodiment, a solenoid actuator 300 is
shown in FIGS. 3A and 3B. As illustrated therein, the solenoid
actuator 300 includes a plurality of coils 301, 302, 303 that are
linearly arranged, end-to-end, along a common central axis 309 with
a gap disposed between each of the coils. In other words, the
solenoid actuator 300 includes multiple non-overlapping coils (the
coils 301, 302, 303) arranged along a common axis. In some
examples, the coils 301, 302, 303 are in close proximity to each
other, for example, being separated by a distance of 1 mm along the
linear axis. In some examples, each of the coils 301, 302, 303 can
have differing turn counts in the coil and/or differing diameters
of the coil, however, in other examples, the coils can have a
similar or identical number of turns and/or similar or identical
diameters.
[0047] As shown in FIGS. 3A and 3B, the coils 301, 302, 303 can
each be connected to separate circuits 304, 305, 306 (respectively)
such that the current for each coil can be individually controlled
and currents I.sub.1, I.sub.2, I.sub.3 may selectively differ
between the coils. Flux densities along the common axis 309 can
therefore be made discontinuous (i.e., variable) along the axis
with a prepondering magnetic flux density biased in order to create
the desired direction of movement for a plunger 308 (i.e., biased
toward a first end or a second apposing end of the solenoid
actuator 300. Due to the close proximity of the coils 301, 302,
303, the magnetic field spans the common axis and the coils 301,
302, 303 can act as a single electromagnet, for example, in a
similar manner to the way multiple smaller permanent magnets can be
stacked to create a field similar to that of a larger permanent
magnet. The power flow to each coil 301, 302, 303 may be altered
through the application of pulse width modulation. In FIG. 3A, the
switches are in the open position 311a, 311b, 311c, and therefore
the potential B field 309 is not yet active.
[0048] Using the solenoid actuator 300, the coils 301, 302, 303
arranged along the common axis can be selectively switched on and
off in a manner that maintains a force on the plunger 308 in motion
by generating, for example, a relatively weak magnetic field at the
same position as the plunger and a comparatively stronger magnetic
field in front of the plunger as it moves along the axis 309.
Additionally or alternatively, in some examples, the magnetic field
can be generated such that a repulsive force acts on the moving
plunger 308 from behind in order to provide additional accelerative
force on the plunger. This may also be effective in reducing the
tendency of the plunger when accelerating to slip out of the spot
or become misaligned when the plunger is experiencing a maximum
accelerative force. Further, a sensor configured to detect a
position of the plunger along the axis can be-utilized for proper
timing of switching the circuits 304, 305, 306 for the coils 301,
302, 303. By controlling the power flow to each individual coil, it
is possible to create a condition of position control along the
axis where the plunger is acted on most strongly by the coil with
more windings and/or more power relative to others of the coils. In
other words, by selectively turning individual ones of the coils
301, 302, 303 on and off, only those coils with active power flow
act on the plunger 308, which allows fine tuning of position
control utilizing e.g., a controller apparatus (such as, the
computerized controller apparatus 1410 discussed below with
reference to FIG. 14). It will be appreciated that the coils 301,
302, 303 can act on the plunger 308 while it is disposed within the
windings and aligned with the common axis 309 (as depicted in FIGS.
3A and 3B) or the solenoid actuator 300 can function similarly with
a plunger that is moving outside of the coils (e.g., along the top
of the coil), as long as the plunger (object) is magnetized or
capable of being magnetized.
[0049] FIG. 3A specifically depicts an embodiment where the plunger
308 is being acted upon by the coils 301, 302, 303 (which are each
on a separate circuit) at a moment in which switches 312, 313, 314
on each of the circuits is moving from an open position 311 towards
a closed position. The current 307 flows through respective
circuits 304, 305, 306 therefore flows through the coils 301, 302,
303. The three coils 301, 302, 303 are separated by a gap 309, and
each of can have a differing current levels (for example, such that
the current I.sub.1 flowing in the circuit 306 is greater than the
current I.sub.2 flowing in the circuit 305, which is greater than
the current I.sub.3 flowing in the circuit 304). These differing
current levels can generate the asymmetrical flux density 316,
which thereby lengthens the stroke of the solenoid actuator 300
relative to convention solenoid actuators, such as the solenoid
actuator 100.
[0050] FIG. 3B illustrates the solenoid actuator 300 after the
switches 312, 313, 314 on the respective circuits 304, 305, 306 are
moved into a closed position 312. A position 310a corresponds to a
location of the midpoint of the plunger before closing of the
switches, while a position 310 corresponds to a location of the
midpoint of the plunger 308 after closing of the switches, which
define the stroke distance 315. As noted above, the stroke distance
315 is greater than that of a conventional solenoid linear actuator
(such as the solenoid actuator 100) by means of the asymmetrical
magnetic flux density, which preponderates towards, e.g., the right
side of the solenoid actuator 300. A winding 307a overlaps with a
part of the coil to illustrate a winding direction of the coil 301.
The switches are shown in the closed position 312a, 312b, 312c in
FIG. 3B, and therefore the active B field 309 is generated and
capable of acting on the plunger 308.
[0051] It will be understood that three coils and circuits are
illustrated in the embodiment of FIGS. 3A and 3B, but in alternate
embodiments the solenoid actuator can include more or fewer coils
and circuits (such as, two or four or more coils and circuits).
Additionally, in embodiments, the circuits may be connected to a
circuit controller, for example, or another mechanism for
generating different field gradients between respective circuits
and therefore differing or creating a gradient in the flux density
of the B-field.
[0052] In embodiments, the solenoid actuators including multiple
coils and circuits (such as in the embodiments of FIGS. 6A and 6B),
as well as the associated methods for introducing nonuniform
magnetic fields may be made more efficient if the coils, which are
behind the plunger, are turned off as the plunger moves past them.
In such embodiments, a non-uniform magnetic field can be generated
ahead of the plunger via the coils ahead of the plunger, however
the fields that the plunger has already moved through are no longer
active, so as to yield an even greater stroke of movement for a
given coil or set of coils. Where multiple coils are used and
switched on and off along a single axis, the coils may actively
reduce the power flow as the moving plunger into the field of a
given coil. In this way, power levels in each consecutive circuit
do not need to continuously increase as the plunger moves along the
axis. Rather, the movement of the plunger can continue as long as
the power levels of the coil just ahead of the plunger maintains a
higher flux than the coil just behind the moving plunger, thereby
maintaining a positive flux gradient in the direction of travel. In
implementations, the nonuniform field may be oriented in such a way
that the axis along which the actuation takes place is in a
screw-like form around a cylindrical object. This implementation
may allow for more torque to be developed along the central the
axis of the cylinder at the expense of actuation length.
[0053] In embodiments, for breaking or slowing of the plunger,
individual ones of the coils that are located behind the moving
plunger can turn on as the plunger moves past them, thereby
attracting the plunger in the opposite direction of its momentum
and causing the plunger to decelerate or stop its movement. Thus,
embodiments disclosed herein can include elements or employ
strategies and methods for resistance to motion along the axis of
travel of a solenoid actuator configured to generate a non-uniform
magnetic field distribution that preponderates toward one end of
the actuator. Further, the embodiments disclosed herein can allow
for a method of producing movements that act against the resistance
for a given power input or time period of power input, which can be
advantageous when small or specific changes in the location of the
plunger are desired. For example, when the source of resistance is
a source of tension or compression between the plunger and a
stationary object in the system, which may be fixedly attached, the
moving plunger can have a displacement that is relative to the
power input or the duration of power input. Further, the plunger
can return to a position that minimizes the tension or compression
through ordinary elastic means when power to the coils and circuits
is turned off. In another example, a load possessing mass or
object, against which it would take power to move, may be attached
to the plunger. Overcoming the resistive losses of moving the
plunger can then take the place of purposefully employed mechanical
or elastic resistance (as in the prior example), as the plunger
having the mass attached thereto can inherently create its own
inertial and mechanical resistance to motion. Diagrammatically this
may take the same form as in the embodiments of FIGS. 2A and
2B.
[0054] In embodiments, two or more coils in a solenoid actuator (or
a linear motor) possessing a non-uniform magnetic field may act to
accelerate the plunger in the above examples in opposite directions
(by having e.g., opposite polarity of the input power and/or
oppositely wound coil directions) so that small changes in the
level of power input or time interval of power input to one or more
of the coils can cause corresponding changes in the position of the
plunger of the actuator or motor. An example of this is illustrated
in the embodiments of FIGS. 8A and 8B.
[0055] In embodiments, the exemplary solenoid actuators disclosed
herein may have any of a moving coil system, a moving magnet
system, or a combination thereof within a non-uniform magnetic
field distribution that preponderates toward one end actuator. For
example, a coil may be of ordinary field distribution or it may be
designed to produce a non-uniform magnetic field as it acts on a
permanent magnet source in a plunger, which itself produces a
non-uniform magnetic field as, for example, the permanent magnet
does in the embodiments of FIGS. 7A and 7B. Alternatively, two of
such permanent magnets or electromagnetic coils may act on the
plunger in the system in a manner that the forces which they
produce on the plunger may be opposite (i.e., in a push pull
topology, similar to that which may occur in the embodiment of FIG.
8) or the forces may be additive (i.e., acting in the same
direction). When one component is held stationary, the other
component is made to move towards or away from the point of highest
flux density depending on the respective polarities of each. A
small coil can, for example, act on a large set of permanent
magnets to produce a wide stroke relative to the length of the
permanent magnetic plunger moving therein. This stroke can be many
times (e.g., 2-5 times) the length of the electromagnetic coil
acting on it. In this example, the permanent magnets in the plunger
may be arranged or attached such that there is a separation between
magnets of various lengths.
[0056] Such embodiments can also, for example, enable production of
a linear motor capable of continual acceleration of the magnets.
When this form of linear motor is carrying a load attached to a
plunger, the load and plunger can be accelerated down a series of
aligned coils. When the load and plunger reach a desired position,
the nonuniform magnetic field gradient can be used to gradually
decelerate the plunger in motion by reversing the polarity of the
coils acting on the load and plunger. In embodiments, smoother
deceleration can be attained using coils that themselves possess a
nonuniform magnetic field gradient along their central axis. In
embodiments, deceleration can also be attained when coils are
turned on at a time so as to attract the peak magnetic field
density of the plunger in motion in an opposite direction relative
to a current direction of travel. Additionally or alternatively, in
embodiments, a repelling action or force on the plunger in motion
from a coil ahead of the plunger in its direction of travel. Thus,
a method of both acceleration and deceleration may be enabled with
this form of linear solenoid actuator or motor. Optionally, the
solenoid actuator can further include or be configured for
communication with a position feedback mechanism or position
sensor(s) and a controller capable of turning power flow on and off
to each coil based on a position of the plunger to selectively
generate either acceleration or deceleration thereof (such as those
discussed below with reference to FIG. 14). In some
implementations, positional holding or control can be possible when
coils acting on the plunger do not turn off, but instead maintain
low a continual power flow. Diagrammatically this set up may take a
form similar to the embodiments shown in FIGS. 2A and 2B, where
multiple actuators of similar construction may be on a single axis
of movement with a spacing of, for example, 1 mm between each
respective actuator.
[0057] Two or more plungers being acted on by co-linear solenoid
actuators or linear motors possessing a nonuniform magnetic field
can be connected using a rigid or semi-rigid member, which may
result in higher total force production, as illustrated in the
embodiment of FIG. 9. The distance between each of the sources of
nonuniform magnetic fields driving the solenoid actuators may be
such that there is minimal interference in the produced magnetic
fields. One or more of the co-linear actuators or motors can be
configured for reversal of polarity and include a mechanism for
adjusting power flow thereto. This can enable production of
counteracting forces on the rigid or semi-rigid member connecting
the plungers of the solenoid actuators and allow for various
positions along the stroke pathway of the plungers to be reached
and held. Specifically, in the exemplary embodiment of FIG. 9, a
rigid or semi rigid member 901 splits into two elbows 902 in order
to connect two permanent magnets 903 which may act as the plungers
in a solenoid actuator 900. Two coils 904 and 905 are constructed
to produce a non-homogenous magnetic field which preponderates
toward opposite ends, illustrated in that coil 904 is facing the
opposite direction relative to coil 905. As power is applied to
these two coils 904 and 905 simultaneously, the plungers 903 are
both imparted a force which may act in opposite directions. As the
average power in each of the coils is altered, the position of the
two plungers can be altered or changed. Maximum force in a given
direction is achieved when the two coils 904 and 905 are imparting
forces on the plungers 903, which are acting in the same direction.
Further, any number of coils and plungers may, in this fashion, be
connected together with the added benefit of increasing the
actuation power. It may be especially advantageous in embodiments
or applications where precise control is desired over a wide stroke
when, for example, additional solenoid coil(s) and plunger(s) are
added to the system which have a displaced position of either the
coil or plunger with respect to the other coils and plungers in the
system. These additional components may allow for forces to be
imparted on the plungers through their connection member (such as,
the rigid or semi-rigid member 901) while they are at the end of
their stroke where the forces acting on them are otherwise
negligible.
[0058] In additional or alternate embodiments, a solenoid actuator
or a linear motor configured to generate a nonuniform magnetic
field gradient can have at least two coils configured for acting in
opposite directions with at least one of the coils being connected
to a circuit with a mechanism for power mitigation for positional
control. Additionally, in embodiments, an on/off switch can be
included in each of the circuits connected to the electromagnetic
coils for the purpose of selectively turning off the power flow and
allowing the other coil(s) of the actuator to take over acting on a
plunger. When two or more counter acting coils are used in a
solenoid actuator, such switches can permit a full stroke or nearly
full stroke of movement in each direction along a linear pathway
(via e.g., turning individual circuits off), as well as enable the
ability to perform discreet actions of small incremental movements
(via e.g., power flow control to the individual circuits controlled
by a controller such as, the computerized controller apparatus 1410
discussed below with reference to FIG. 14). An example of this is
shown in the embodiment of FIGS. 8A and 8B.
[0059] In additional or alternate embodiments, an electromagnetic
spring can be formed when a coil has a larger number of windings at
each end thereof. Such coil geometry can create a bipolar
non-uniform magnetic field, which can have a stronger magnetic
force acting on a plunger as it strays from the midpoint of the
coil. When at either of the end points, the plunger in motion
(which may be a magnetic, ferromagnetic, or electromagnetic object)
can be forced to change directions. The plunger may experience
forces that arrest its momentum and then return the plunger to the
midpoint. Mounting forces towards the ends of the coil in the
solenoid actuator can allow for this to be done in a more effective
manner relative to a conventional solenoid actuator. Not only can
the plunger experience a returning force that draws it toward the
midpoint of the coil from the magnetic equilibrium that exists
there, but the plunger can also be acted on by the nonuniform
magnetic field, which itself can cause motion in electromagnetic
systems. It will be appreciated that similar result can be achieved
via an actuator embodiment including multiple coils aligned on a
similar axis (such as the solenoid actuator 300 illustrated in
FIGS. 3A and 3B) when a greater current density is applied to the
coils at opposing ends of the plurality of coils. An exemplary
embodiment of this may be nearly identical to the embodiment of
FIGS. 8A and 8B except that the two circuits may be joined by one
power source such that the field produced by both sets of coils is
additive.
[0060] As discussed above, in embodiments, a coil can have one or
more adjacent coils, which also have power flowing therethrough,
which can, by applying differing the power levels to the coils,
alter their respective influences on a plunger (e.g., a magnetic or
paramagnetic object or objects). However, in alternate embodiments,
a more potentially more cost-effective method of controlling the
position of a plunger in a solenoid actuator or a linear motor
having a plurality of coils can be configured to have an increasing
number of windings and/or coils toward one end of the solenoid
actuator or increasing power flow toward one end of the solenoid
actuator. In such embodiments, variable power sources such as, for
example, a battery and a potentiometer, can cause a plunger in the
system to have a varying amount of attractive or repulsive force,
which can drive movement to a new location. Automated control of
the solenoid actuator can be made, for example, by attaching a
motor to the potentiometer and driving the motor from a
computerized controller (such as, the computerized controller
apparatus 1410 discussed below with reference to FIG. 14) capable
of causing incremental changes in a position of the motor. In
implementations, separate batteries of different power ratings can
be connected to the circuit(s) with switches, which may be
controlled using the computerized controller. It will be understood
that other types of variable power supplies and methods such as
pulse width modulation can be used in combination with the
actuators disclosed herein, and the disclosure is not limited to
the above examples. An example of this type of actuator is
illustrated in the embodiment of FIGS. 8A and 8B.
[0061] In embodiments, in order to add non-linearity to the
magnetic flux distribution, the material of the coil's core may be
altered. A core of a coil can contain a material that increases
inductance of the coil. The material can be used to influence the
inductance of some windings in a coil more than others. For
example, when a solenoid actuator comprising nonuniform magnetic
fields along the stroke is comprised of two or more electromagnetic
coils acting on one another, it may be desirable for the coils to
be similar in configuration to coils in a conventional solenoid
actuator, but to include a core composition in a section of the
windings including a material (which may, for example, be
ferromagnetic) in order to increase the inductance of some windings
relative to others of the windings. For example, the coil can be
configured to have more of the inductive material in windings at
one end of the coil relative to the windings at the opposing end of
the coil. Such a configuration can increase the non-linearity
towards one side of the coil (i.e., a side of the coil having the
inductive core) in order to increase the stroke length of the
coil.
[0062] In an illustrative example, a cylindrical dowel that can be
hollowed out in a manner that leaves more volume on one end with
relative to the opposing end. The hollowed space can be filled with
a material that is capable of influencing the inductance of the
nearby windings such as, for example, ferrite powder. A coil can
then be wound on top of the dowel. The coil can thereby be
configured to maintain an asymmetrical flux density along its
length without the use of different coil geometries or multiple
circuits. In embodiments, primary coils with cores having such a
configuration can have separate, secondary coils moving outside of
them (such as, on the top of the primary coils) while the primary
coils are held stationary. Such coils may also produce a magnetic
field with asymmetrical flux density in other to further increase
the stroke distance of the solenoid actuator. Further, in
embodiments, coils and/or magnets that may or may not produce flux
densities that vary over their lengths can be acted on by another
coil or magnet, which itself produces a non-uniform magnetic field
density in order to increase the stroke of movement of an object (a
plunger) in motion through a solenoid actuator. For example, as
depicted in FIG. 10, a cylindrical coil core 1001 has a portion
1002 of its that is volume hollowed out and filled with a material
of a different magnetic permeability than the rest of the core
(illustrated in cross hatching). The whole core 1000 can then be
utilized to wind a coil over. In embodiments, the coil can then
produce a nonhomogeneous magnetic field due to the magnetic
permeability changing over the length of the cylinder 1000. This
magnetic field may then be acted on by a permanent magnet, which
may be ring-shaped so as to travel along the length of the coil
that is wrapped on the core 1000. The coil and core may also be the
plunger in an actuator system when the other source of a magnetic
field acting on it is held stationary. Accordingly, a coil wrapped
upon a core such as this acts in many ways like the magnetic field
produced from other embodiments such as that depicted in FIG.
2A.
[0063] In another embodiment, a solenoid actuator can have multiple
taps along its length similar to an autotransformer. The foregoing
solenoid actuator can be configured for use with a power source and
a controller (such as, the computerized controller apparatus 1410
discussed below with reference to FIG. 14) to create non-uniform
magnetic fields for the purpose of increasing the stroke in one or
more coils of the solenoid actuator. A first end of a coil may be
connected to the negative terminal of a first battery, and a second
opposing end of the coil can be connected to the positive terminal
of the first battery so that the battery supplies power to the
length of the coil. A first tap that is, for example, one third of
the way down the length of the coil from the first, can be
connected to a positive terminal of a second battery, and the
negative terminal of the second battery can be connected to the
negative terminal of the first battery. Accordingly, the second
battery provides power flow through the corresponding one third of
the coil, which is in addition to the power flow therein provided
by the first battery. A second tap may be, for example, two thirds
of the way down the coil from the first end. The second tap can be
connected to a positive terminal of a third battery. A negative
terminal of the third battery can be connected to the same terminal
that the other batteries are grounded through, therefore the third
battery's power flow is contained within two thirds of the solenoid
length. This embodiment of a solenoid actuator can therefore
comprise three distinct current flows over the coil as each of the
three batteries operates in a commensurate fashion over a
respective portion of the coil across which it is connected. In
this exemplary embodiment, a single layer coil can be configured to
generate a non-uniform magnetic field distribution using a power
source (e.g., three batteries). In some implementations, additional
switches can be configured to switch the polarity of each of the
batteries so as to reverse the forces in the system acting on a
plunger. Further, in additional or alternate implementations, by
incorporating methods of controlling the power flow out of each
battery (such as, via a connection through a potentiometer and
another on/off switch), fine tuning of the plunger's position may
be possible. For example, FIG. 11 illustrated a solenoid actuator
1100 that possesses of a coil with a construction very similar to
that of an autotransformer except that it can be configured to
produce a nonhomogeneous magnetic field along its length. The coil
1104 can have multiple taps along its length 1103a, 1103b, and
1103c between which power is distributed in a non-linear fashion.
The power sources 1101 and 1102 can have different numbers of power
cells that are configured to cause more power to flow between taps
1103b and 1103c than there is power flowing between 1003a and
1103b. This produces a magnetic field density that varies along the
length of the coil 1104. In alternate embodiments, a greater number
of taps can allow for a finer adjustment of the magnetic field
density gradient which exists along the length of this coil.
Variable power sources which alter the average power through a
given section can provide a mechanism to alter a plunger's position
within the coil, especially when the plungers position is being
monitored and/or controlled via a controller (such as, the
computerized controller apparatus 1410 discussed below with
reference to FIG. 14), and where data is used to control or vary
the average power through the various taps on the coil 1104.
[0064] Furthermore, in additional or alternate implementations, the
foregoing embodiment of a solenoid actuator can include a core
within the coil that is configured to enable a changing or variable
magnetic permeability and/or distance from the coil to the core
along the length of the coil. This can allow for a single coil to
create an asymmetrical magnetic field density on a surface of the
coil by augmenting the influence of the core to the coil's
inductance at various points along the length of the coil. A
plunger can therefore move over the surface of the coil (e.g., over
the top of the coil) in a similar manner to the motion of the
plunger in other embodiments, wherein the plunger experiences a
force that drives it towards or away from the point of highest
magnetic flux density, depending on the polarities of the plunger
and the coil. The asymmetry in this example may also increase the
stroke of the solenoid actuator so long as the inductance
preponderates from one end of the coil to the opposing end. Such an
embodiment can be useful in applications where a plunger moves over
the top of a solenoid since the coil may be linearly wound and have
one circuit, which therefore enables the distance between the
plunger and the coil to be minimized and the simplifies the
construction of the solenoid actuator.
[0065] Turning now to FIGS. 4A and 4B, a linear actuator 400
including a conical object 401) is depicted therein. As shown in
FIG. 4A, the conical object 410 is can be comprised of metal and
can include a hollow metal tube 402 disposed therein and aligned
with a central axis of the cone. FIG. 4B depicts the conical object
401 as it slides along in contact with an electrified rail 408
towards a plurality of insulated electrified rings 409, which can
have an opposite electric polarity relative to the conical object
401. The insulated electrified rings 409 can be connected to a
voltage source 403 in a manner that enables each ring to have a
different voltage potential. The voltage potentials may be
dependent on, for example, a number of batteries (e.g., batteries
V.sub.1-V.sub.n) connected to the linear actuator 400 and/or their
respective properties. A non-uniform magnetic or electrical field
can be generated when the rings 403 create a non-linear function of
forces based on, for example, their respective voltage potentials
and/or their distances to the conical object 401 as it moves along
the rail 408. A capacitive nature or relationship may exist between
the rings 403 so that as the conical object 401 approaches them,
arcing is limited and a difference in electrical potential exists
between the respective ring 403 and the conical object 401. The
electrical potential is positive on one side 404 of the power
source and negative on the other (opposing) side 405 when a DC
power source such as a battery is used. A circuit 406 can be formed
when motion results in closing of a switch 407. Such motion can be
a result of the nonuniform fields generated by the conical shape of
the conical object 401 and its attraction to the insulated rings
403. Energy is, in this exemplary embodiment, can be drawn from the
batteries and can be consumed via a capacitor with an imbalance of
forces acting upon it due to the conical shape of the conical
object 401. Motion energy can be further aided by the use of high
voltage sources of electric potential.
[0066] In one exemplary application, an object that is intended to
accelerate incrementally, such as a linear actuator moving a
delicate object where sudden changes in the forces create impulses
which are undesirable, can be implemented using a configuration
similar to the linear actuator 400 (or configurations similar to
other linear actuators disclosed herein), as force therein may be a
product of factors such as the field density and the current at a
given point along the stroke. As these factors can be made to vary
with an asymmetrical distribution, naturally incrementing speeds
are possible. The acceleration curves of objects in the system can
be tailored to the application, for example, an inverse square
curve can be utilized and efficient results. An exemplary curve
1200 is depicted in FIG. 12 where either the electric or magnetic
fields (depending on the embodiment) are varied with respect to
distance by the inverse square function.
[0067] In another exemplary application, objects that are in
rotation or pivoting around a joint can utilize asymmetrical field
distributions along the stroke for the purpose of increasing the
stroke (discussed in detail below with reference to FIGS. 5A and
5B). In this example, asymmetrical distributions of magnetic field
density or current density of the stator, rotor, or both can result
in motion of an object. Unlike convention actuators, the exemplary
applicant can exclude motors and/or gears and instead use solenoid
interaction, which may enable simpler and/or less expensive
manufacturing. For example, in a rotating joint with a direct
current application, the motion can cease when the coil(s) with the
highest flux density acting on a system with non-constant flux
distribution of the object in motion aligns with the point of
highest flux density on a stationary portion of the system. The
embodiment can also be applied to a motor if the stationary portion
of the system, namely a coil acting on the system, is pulsed or
switched off incrementally (for example, from a commutated
connection like a commutated DC motor) when the point of highest
flux density of the stationary and moving portions of the system
align. As the alignment of the stationary and moving portions of
the system can ordinarily cause the cessation of movement, a
constant rotation can be produced by turning the coils off during
this part of the rotation. In implementations, the rotating member
may have springs attached to return the object in motion back to a
previous (e.g., initial) position when the power level is changed,
thereby enabling an object to rotate up to nearly one revolution
before stopping when it is exposed to a nearby magnetic field. In
rotating actuator systems such as these, the asymmetric
distribution of magnetic force along the axis of rotation can lead
to vibration at higher RPM. In implementation, the vibration can be
mitigated by placement of counterweights on the rotating body. In
additional or alternate implementations, vibration can be mitigated
by using several similar arrangements (one next to the other) on a
shared rotating body where each arrangement of coils or permanent
magnets is at a different point in its acceleration curve from coil
or permanent magnet located next to it.
[0068] In embodiments, rotational solenoid actuators configured to
generate a nonuniform magnetic field gradient for the production of
motion can comprise two coils of different polarity and/or winding
direction, which are positioned near each other. This can allow for
a permanent magnet or electromagnet to have each pole acting on or
interacting with one of the two coils concurrently for more
efficient force production through the simultaneous utilization of
both magnetic poles. An exemplary embodiment of a form of winding
for coils that produce a nonuniform magnetic field gradient along
the diameter of a rotational linear actuator can be achieved via,
for example, having multiple coil bobbins extending radially out of
the actuator, which may be non-magnetic. Further, a coil can be
wound such that two or more neighboring bobbins have a winding
wrapped around them with a next winding wrapping around fewer
bobbins than the preceding winding, until a winding is wrapped
around a single bobbin. In embodiments, the progressive wrapping
around fewer bobbins until reaching the single bobbin can be
repeated one or more times with the same wire or an attached wire.
This coil geometry can generate a nonuniform magnetic field that is
progressively greater as it approaches the coil bobbin with the
most windings around it and may act on one pole of a permanent or
electromagnetic source. In embodiments, this form of coil may have
a neighboring coil of the same geometry to act on the other pole of
the permanent or electromagnetic source, which can, as discussed
above, result in increased efficiency of the rotational linear
actuator. This geometry is related to the embodiments of FIGS. 8A
and 8B, as well as the exemplary rotational actuators of FIGS.
5A-5C.
[0069] FIGS. 5A-5C depict an exemplary embodiment of a rotational
actuator apparatus 500, which is designed to actuate a rotating
member 501. The rotating member 501 can be configured to rotate
around a central axis of rotation 511 through the interaction of a
first magnetic field around the rotating member 501 with a second
magnetic field generated by a separate coil 507 when one or both of
the first or second magnetic fields is a non-linear field gradient
in the direction of rotation. In this embodiment, the magnetic
field around the rotating member 501 is can be a source of a
nonuniform magnetic field due to geometry of its coil 504. In
implementations, the coil 504 is segmented in a configuration that
can generate a peak magnetic flux density toward one end of the
coil 504 and a minimum flux density on an opposite end thereof. The
coil 504 can be connected to a power source 503 through connecting
wires 504 and 504a. Similar to the rotation linear actuator
described above, the coil 504 is wound around a plurality of
bobbins 505a-505e so that a number of windings around the bobbin
505a is greater than the number of windings around the bobbin 505b.
Further, a number of windings on each subsequent bobbin is less
than the preceding bobbin (for example, the bobbin 505a has a great
number of windings than the bobbin 505b, which has a greater number
of windings than the bobbin 505c, which has a greater number of
windings than the bobbin 505d, which has a greater number of
windings than the bobbin 505e). This configuration results in a
single coil (i.e., the coil 504) configured to generate an area of
peak magnetic field density that is displaced relative to the
center of the coil (i.e., towards one end of the coil 507). The
separate coil 507 is connected to a power source 508 through a
switch 509 (in FIG. 5A the switch 509 is shown in an open position
509a). The coil 507 can be configured to generate the second
magnetic field for interaction with the first magnetic field
generated by the rotating member 501 so as to rotate the member 501
towards a point (e.g., a position of 505a) where the peak magnetic
field lines up with the stationary magnetic field of the coil 507.
The side elevation view of FIG. 5B depicts a side view the
rotational actuator apparatus 500 including an actuator 502.
[0070] FIG. 5B depicts a side view of the rotating member 501,
illustrating the geometry of the coil 504. As can be seen therein,
each consecutive winding is wrapped around on consecutive ones of
the bobbins 505a-505e, thereby resulting in each winding being
different distance from the first bobbin 505a. Further, the
configuration results in the bobbin 505a having the most windings
(the greatest number of windings) in contact therewith, and
therefore is the location of greatest magnetic field density is in
the area of the first bobbin 505a.
[0071] FIG. 5C depicts the rotating actuator 500 after the switch
is moved to a closed position 509b causing rotation of the
rotatably member 501. Specifically, the rotatable member 501 can be
rotated such that the peak magnetic flux density (located at the
bobbin 505a and corresponding to a magnetic north pole of the coil
504) is aligned with a magnetic south pole of the coil 507. The
direction of rotation 512 about the central axis 511 depicts the
movement that occurred after or when switch 509 is in a closed
509b.
[0072] In implementations, this embodiment can include a spring
within the rotating member 501, which can enable actuation which
returns an object to a predetermined position without switching the
polarity of the coil 507. In such implementations, a distance of
rotation of the rotating member 501 can be controlled (and varied)
by selecting specified power levels that partially overcome the
spring's tension, which may be selected via e.g., a controller
apparatus (such as the computerized controller apparatus 1410
discussed below with reference to FIG. 14). Alternatively or
additionally, the actuator 500 can include a flexible cable, which
may be the moving object in the system. The flexibility of the
cable allows for of the actuator to be used for various
applications, especially those in which the flexibility is needed
or beneficial. Examples of where flexibility may be beneficial may
be where a moving object in the system needs to make a turn, such
as in e.g., clothing or some robotic systems. In such instances,
the flexible cable can form a non-linear central axis of actuation.
An example of this would be the addition of a spiral spring to the
actuator apparatus 500 of FIGS. 5A, 5B, and 5C. For example, a
spiral spring may be rigidly mounted on a stationary member on one
end and attached to the rotating actuator on the other. Turning off
the power or reducing the average power may allow for the rotating
object to completely or partially return to a predetermined
position. Further, the spring may be designed to take the rotating
member from the end of the actuation stroke to the beginning so
that it may be acted upon by the coil without a polarity reversal
being necessary.
[0073] In other implementations, the actuator 500 can be used in
combination with hydraulic or pneumatic actuators to increase a
force produced by the combined actuator and/or reliability of the
combined actuator. For example, during use, strain may be lowered
on one or more components of the system. In another example, one
actuator may act as a backup to the other actuator in an instance
where one fails.
[0074] In still other implementations, the actuator 500 can be used
in voice coil actuators in conditions where an asymmetrical field
density may be desirable. The asymmetrical field density actuator
may be simpler to operate than a conventional voice coil type due
to the ability to use DC from more simple power sources and to make
the object or plunger in motion perform a variety of movements,
such as omni and/or bi-directional movements. It may also be
possible to produce the asymmetrical field density solenoid
actuator in a lower cost manner than a typical voice coil., and/or
in other applications related to vehicles, including in internal
combustion engine valves, fluid pumps, fluid valves, oscillators,
projectiles, automatic surface leveling, and/or in suspension
systems. The form of the actuator may take that of the embodiments
of FIGS. 2A and 2B.
[0075] The rotatable actuator 500 (as well as other actuators
disclosed herein) may be more compact for use in a given
application relative to conventional actuators. Further, the
rotatable actuator 500 (as well as other actuators disclosed
herein) may reduce a gap in time within which the object in motion
receives little or no driving force (due to its position coinciding
with either peak or minimum magnetic flux density) when there are
multiple coils along a single axis. In contrast, in conventional
actuators, an object or plunger can only travel in one direction
and may be acted upon by multiple co-axial coils as the coils
switch on and off as the object reaches the halfway point along the
length of a respective coil. The asymmetrical field density design
of the actuators disclosed herein may address these issues. In the
embodiments of FIGS. 5A, 5B, and 5C, this would take the form of
one or more additional coils similar to coil 507.
[0076] FIGS. 5A, 5B, and 5C can represent an embodiment of an axial
flux actuator. Although this design of an axial flux actuator takes
place around an axis of rotation, the same actuator can function in
a linear motion application as well. This may be advantageous in
applications where the plunger and the coils are not required to be
constrained by the solenoid windings being wrapped around the
outside of the plunger or with the plunger being positioned on top
of the solenoid windings. It may also be advantageous to adopt this
form of linear actuator when spatial constraints limit the length
of the rigid or semi rigid piece which connects the object which
needs motion imparted to it and the plunger of the actuator. This
reduced spatial constraint is the result of the configuration of
the coil windings. Further, both poles of permanent magnets may be
used to act on both poles of the magnetic field produced by a coil
wound in a manner similar to that of the embodiment of FIGS. 5A,
5B, and 5C.
[0077] In other embodiments, pulsed DC can be used in combination
with actuators configured to disclosed herein for thermal
management. Additionally, the actuators disclosed herein can be
used in combination with housings having cooling systems embodied
as metal vanes or hollow bodies containing the coil(s), which are
equipped for cooling fluid being pumped therethrough.
[0078] The actuator, rotating joint, or motor may also have
provisions for locking in place. This allows for no energy to be
consumed when the actuator is holding a predetermined position.
[0079] It will be appreciated that the components of the actuators
disclosed herein can be implemented in forms other than linear and
rotational actuators. For example, other magnetic systems of force
can may be configured to include features of the actuators
disclosed herein in order to implement non-linearity which can aid
in the duration of applied forces, as well as tailoring of the
slope of the forces. Since each subsequently peripheral coil adds
onto the field of the coil beneath it, a function of combined or
additive forces (i.e., the sum of each of the individual coil's
forces) may be formed by the system. As more non-linearity is
introduced into a coil system design, the generated magnetic field
and the subsequent force profiles follow suit.
[0080] Further, the profile of the non-linearity of flux potentials
can be suited to the application for which the linear actuator (or
another actuator) is required. For example, it will be appreciated
that a certain function of flux density distributions may be
especially well-suited to an application, and the distribution can
take the form of the inverse square curve (i.e., 1/d{circumflex
over ( )}2). Various other flux distribution patterns may be used
where applications desire a particular profile of forces on an
object or plunger in motion. A specific example of an application
where this trait may be desirable or useful is with an object that
must be made to resist certain strains as it is actuated, where
these strains do not increase in a linear manner but are instead
varying in an exponential manner over the stroke of actuation.
[0081] Another feature of disclosed herein can be gradual and
successively greater acceleration that is experienced by a moving
object or plunger. The successive accelerations progressively
stacking up may yield a greater efficiency of force transference
onto the object or plunger than a strong impulse of force of a
constant amplitude. The added efficiency can be gained by the
integral of the acceleration function being larger than a
comparable coil. The reason for this increase in efficiency may at
least in part be due to fact that the limits of the function of
applied force are twice that of an ordinary coil since the object
or plunger is capable of being acted upon for nearly twice the
amount of time while it is within the primary coil.
[0082] In applications where optimum efficiency is desired, the
linear actuators or other actuators disclosed herein can be
provided with coils, which are wound in a bifilar fashion in such a
way as to increase the field density of a coil for a given number
of turns as is described, for example, in the U.S. Pat. No.
512,340, which is incorporated by reference herein. This can allow
for less materials to be used in the creation of an actuator of a
certain desired force. A further increase in efficiency can be made
by distributing the field density in a manner that corresponds to
the inverse square law, thereby imitating the natural magnetic
field distribution of a permanent magnet.
[0083] FIGS. 7A and 7B illustrate a linear actuator 700 that
includes a magnet 701 (comprising of a series of permanent magnets
701a, 701b, 701c, 701d) configured to produce the asymmetrical flux
density, wherein a coil 703 with electric potential is applied to
the linear actuator 700 to produce motion of either the permanent
magnets 701a, 701b, 701c, 701d or the coil 703 itself. As can be
seen in FIG. 7A, the cylindrical permanent magnets 701a, 701b.
701c, 701d can each have a different diameter and connect together
so as to form a single magnetic dipole. The variation in diameter
can augment the magnetic flux density experienced by the coil 703
from the magnet 701 in such a way as to create a nonuniform
magnetic field along its length. A circuit 705 in communication
with a current source and a switch 706 can allow the stationary
coil to act on the magnet 701 so as to produce a linear actuator
with a wider stroke (relative to a conventional linear actuator) as
a result of the augmented profile of the magnetic flux density
along the permanent magnet's length.
[0084] FIG. 7A illustrates the switch # in a closed position 706,
while FIG. 7B depicts the linear actuator 700 in a state where the
switch 706 is in an open position 706a and is moved into a closed
position 706b. When in the closed position 706b, power flowing
through the coil can act upon the magnet 701 and causes them to
move nearly the full length of the way down the coil 703. A South
pole 708 of the magnet 701 can extend outwardly from front of the
end of the coil 703 after the magnet 701 has moved its full stroke,
and the North pole 702 can be aligned with the back end of the coil
703.
[0085] Without departing from the scope of the present disclosure,
a toroidal coil could be used in the linear actuator 700, which may
employ a core. The toroidal core may be beneficial when ultra-fast
movement is desired, on account of the inherently higher quality
factor, which make them predisposed to fast switching of polarity
or power levels. Additionally, or alternatively, Litz wire may also
be used to this end. The diagrammatic representation of this may
not depart from the embodiment shown in FIGS. 7A and 7B, where the
coil is a toroid instead of an ordinary solenoid.
[0086] In order to lower the weight and/or the cost of the linear
actuator 700, the magnets 701a, 701b, 701c, 701d can be connected
with iron rods, which may be hollow to create a virtually longer
permanent magnet. Additionally or alternatively, electromagnetic
solenoids can be used in place of the permanent magnets (with or
without magnetizable cores). For example, the electromagnetic
solenoids can be of classic construction or asymmetrically
constructed to suit a particular force profile of the application.
In implementations, longer life due to a lack of magnetic force
deterioration found in permanent magnets may be provided at the
expense of power consumption when EM solenoids are used in place of
permanent magnets in the actuator 700.
[0087] Turning to FIGS. 8A and 8B, a linear actuator 800 is shown
and described. In applications where precision of movement is
desired, two coils may be used, which are oppositely magnetized. In
such a configuration, the power of each coil can be biased so that
one coil predominates using electric control systems capable of
intelligent computation of movement and precise actuation of power
(such as, the computerized controller apparatus 1410 discussed
below with reference to FIG. 14). Such control systems are known
use in screw type actuators. The coils can be on different axes of
movement and can be connected together through a rigid or
semi-rigid mechanism to prevent the distortion of their respective
fields.
[0088] FIG. 8A the linear actuator 800 includes a first coil 820a
comprising three sets of windings 801, 803, 805 on a first circuit
and a second coil 820b comprising three sets of windings 802, 804,
806 on a second circuit, which are each disposed along a single
axis 807 and configured to act on a plunger. Specifically, the
first and second coils each consist of an inner winding 801, 802
that stretches the full length of the actuator 800, an intermediate
winding 803, 804, and an end winding 805, 806. Two non-uniform
magnetic fields can be created utilizing the linear actuator 800,
which have their peak flux density at opposite sides of the coils.
Each of them can act on a plunger in such a way that the coils push
or pull on it simultaneously.
[0089] FIG. 8B shows the foregoing coils (circuits) 820a, 820b each
connected to a power source 808, 809, and each with a potentiometer
810, 811, which can be used in the actuator 800 to augment the
power flow of each coil. This can enable biasing of the forces
acting on a plunger in order to augment the stopping position of
the plunger along the stroke. As discussed above, each coil 820a,
820b consists of three sections or groups of windings, where, in
addition to having different length, the sections of windings have
different diameters relative to other sections in the coil, as each
section of windings is wound over the previous group of windings.
When the potentials of one or either coils 820a, 820b are
augmented, it can cause the plunger(s) in motion to be attracted to
one end or the opposing end of the actuator 800 in proportion to
the ratio of flux density produced between the two coils. It will
be understood that other configurations and/or methods of altering
the flux density of one or both of the coils 820a, 820b may be
used, such as including and utilizing a variable power source. In
examples, a selected ratio of flux density can be used to control
power delivery to one or both of the coils 820a, 820b via a
controller apparatus (such as the computerized controller apparatus
1410 discussed below with reference to FIG. 14), which can be
further utilized to control a position of the plunger(s). It will
be further understood that the direction of winding of the coils
and the manner of application of electric potential can be reversed
without departing from the resulting motion that is produced.
[0090] It will be yet further understood that heat generated by a
coil or coils in the linear actuator 800 (or other actuators
disclosed herein) giving rise to nonuniform field distributions may
be greater where the field densities are greatest. Accordingly, in
implementations, enclosures for cooling fluid to flow through may
be incorporated into the actuator. Similarly, in alternate or
additional implementations, vanes can be used, which may be longer
at the points of greatest field density, to aid in the cooling of
the coil(s). Further, in additional or alternate implementations,
watertight enclosures may be used for a given application. Pulse
width modulation may be used to alter the position of the plunger
through its application to one or both circuits.
[0091] In implementations, the linear actuator 800 (or other
actuators disclosed herein) can be used for the gradual absorption
of high impulse forces. A permanent magnet (plunger), which is made
to move through a coil that includes progressively more or layered
windings, may experience a progressively increasing reluctance to
movement from the increasing back-EMF. This may be similar to
compression of a spring except that the energy is not stored
kinetically through tension, though it may be generated and stored
electrically depending on the configuration of the impulse
absorbing apparatus. For example, one configuration may have a coil
actively resisting the motion using electromagnetic fields produced
by a power source, whereas another configuration may have a passive
coil where the permanent magnet encounters a greater back-EMF as it
travels along the length of the coil containing more (or less)
windings toward one pole or one end thereof. The latter
configuration may provide an electrical generating potential and
the former may provide greater force retardation of the moving
plunger. High impulse forces may therefore be absorbed and the
density of the windings along the coil can be tailored for gradual
slowing of the plunger, which would otherwise experience a more
rapid decrease in speed, and thereby lower the force impulse.
Another example of impulse reduction may be a configuration where a
coil with nonuniform flux density is energized and a soft iron bar
(plunger) is imparted some force as it moves through the coil. In
this example, the coil may resist the movement of the iron bar
proportionally to the field at a given point. As the field is not
linear, the force may experience a changing reluctance of movement,
which may lower the impulse curve of the force on the bar. In
implementations, multiple coils with variable power sources can be
used to change the gradient of the magnetic field to further tailor
the reluctance to the force imparted on the magnetized object
(plunger) in real time. Further, the coils may be configured in a
way in which an impact triggers a circuit to turn on through the
physical shock or through the dislodging of an object that was
breaking the circuit. Multiple such objects can be used for
multiple circuits. The form of this embodiment may not depart from
the form shown in FIGS. 2A and 2B.
[0092] This type of actuator may be particularly well-suited to
applications where the force exerted on the actuator by a system is
not constant. An example of this application includes, e.g.,
crushing of an object, stretching of an object with some degree of
elasticity, and repelling of a magnetized object from a single pole
of a coil system.
[0093] In implementations, the linear actuator 800 (or other
actuators disclosed herein) can be used for the rapid movement and
levitation of magnetized objects in space. For example, an object
can be placed in a space surrounded by an actuator that produces a
magnetic field, such as being placed in one or more coils. The
coils can be turned on and off with a polarity and frequency
corresponding to the object's position in space in such a way that
the object is attracted to a denser magnetic field in the direction
of the desired trajectory of the object. The object may be, for
instance, a spherical magnetic object suspended against gravity
with the north and south poles perpendicular to the pull of
gravity. Multiple coils, which themselves may be comprised of one
or more individual circuits for further fine tuning of the field
density (as in, e.g., the exemplary embodiment of FIGS. 7A and 7B),
are positioned around the object. As the spherical object fall
towards the bottom of the actuator, a series of coils can produce
fields that create a field density distribution that pulls both the
north and south poles upwards. As the object rises, the coils can
turn off, causing the object to crest and fall. When the field
gradient is not parallel with the pull of the object, a spinning of
the spherical object can occur and a subsequent wobble of the
object on its axis would occur. Provided that there is some
mechanism for keeping track of where the object is in space and
where the poles are located, the forces from the coils can continue
to keep the spherical object aloft. It will be understood that the
object may be of any shape and it may be paramagnetic,
electromagnetic, or contain permanent magnets. The magnets may have
a desired distribution configured such that fields are created with
a magnetic flux distribution pointed in the desired direction of
travel.
[0094] In implementations, a computer can be utilized in
combination with the linear actuator 800 (or other actuators
disclosed herein) to predict the trajectory based on past or
present locations and switch the power to the coils accordingly to
move the object (or plunger) in an intelligent way. Further, in
implementations, more than one object (or plunger) can be moved in
this way provided that there is sufficient data collected from the
moving objects. A predictive model can be found, which allows the
computer to operate independently of real-time position centers
provided it has the previous location data of an object. In
examples, using this configuration multiple small objects can
maintain an orbit around a central magnetized object. The central
object can include, for example, multiple coils pointed in
different directions radially outward, each with individual
circuits attached to a computerized controller (such as e.g., a
computerized controller apparatus 1410 discussed below with
reference to FIG. 14). Coils on the periphery can act on the moving
magnetized objects to maintain spatial orientation. In this type of
actuator, a model of planetary motion can be made where elliptical
orbits of the moving magnetized objects are brought about through
the use of rapidly fluctuation magnetic fields with intelligently
controlled field density altering the objects trajectory by
creating denser fields in the desired direction of motion. Both
attraction and repulsion can be used in such an actuator to cause
the desired motion. The objective may be to minimize distortion of
the respective trajectories by keeping the moving objects polarity
aimed in the same direction throughout the course of movement. For
example, a model of a liquid vortex can be applied to the
computer's trajectory algorithm since a floating object dropped
into a liquid vortex points the same direction continually as it
swirls around the central axis.
[0095] In implementations, instead of using magnets in an actuator,
which creates flux distributions to move objects intelligently in
three dimensions, ionized particles and plasma may similarly be
controlled. The electric field distribution may be augmented in
such implementations. There may be little or no limit to color
density and/or speed of movement other than the strength of the
field at a given point in the designated space. For use with
plasma, vacuum containers with a mechanism for augmenting the
potential dynamically at a given point and to high flux levels may
be utilized for the maximum adjustability. This configuration and
method can be used in the acceleration of particles in, e.g., a
particle accelerator. Sound waves may be incorporated to add
another layer of control to these actuators by creating compression
and rarefaction, which may influence the ionized particles density.
An exemplary embodiment showing acceleration of ionized particles
over a wider length due to a nonhomogeneous electric field is
depicted in FIG. 13, discussed further below.
[0096] In implementations, the linear actuator 800 (or other
actuators disclosed herein) can be used for extension of the length
of a dielectric barrier discharge as, for example, in a plasma
actuator. A dielectric barrier discharge can be increased in length
by the application of nonlinear voltage distributions on a charged
conductor that is sheathed under a dielectric barrier. Plasma
actuators, which use a dielectric barrier discharge in order to,
for example, influence fluid flow of the surrounding medium, can by
this method extend the influence of the plasma on the fluid medium
through the relatively longer length of travel, which the ionized
plasma is made to be conveyed upon by the introduction of the field
asymmetry. The configuration and method for producing the
nonlinearity of the field in this example may be through the
influence of mutual capacitance of a secondary source on the
sheathed conductor. The mutual capacitance can cause a change in
the charge distribution along a surface of a conductor and
therefore a change in the voltage distribution along the conductor.
The secondary source may provide a mutual capacitive influence over
a small portion of the surface of the sheathed conductor when it is
desirable to cause a change in the voltage distribution only over
the small portion of the conductor. Multiple other voltage sources
may be employed that may have different voltage levels when it is
desired for the dielectric barrier discharge to have a particular
or dynamic distribution of the plasma along the discharge axis. It
will be appreciated that the mutual capacitance in the system,
which produces the nonlinear field, may be a function of voltage
and surface area, so either may be augmented to change the field
distribution. This is shown in FIG. 13 where a plasma actuator 1300
is constructed of an upper electrode 1301 which is exposed to the
flow of a fluid over its surface. A dielectric 1303 separates that
electrode and a second electrode 1302 which is shaped so as to
provide an increasing electric field density to the ionized
particles traveling from the first electrode 1301 as they travel
further over the surface of the dielectric. This can increase the
effectiveness of the plasma actuator in acting on a fluid medium by
widening the plasma actuators range of influence on the fluid
body.
[0097] Alternatively, in implementations, one of the electrodes in
the plasma actuator can have multiple sections of the conductor
separated by the dielectric (as the exemplary embodiment in FIG.
5). Each of the conductors may have a separate voltage from a
suitable high voltage source. The charge may be predominating in
one direction. Accordingly, the dielectric barrier discharge may
tend to redistribute its density to favor the direction of the
higher voltage conductor. The benefits of this implementation may
include the functioning of a dielectric barrier discharge plasma
actuator at relatively lower fluid medium speeds and with
relatively higher efficiency, both of which may be a result of the
longer field of influence for a given plasma actuator. Further, it
may be applied to the exterior of vehicles or aircraft to influence
the drag coefficient more effectively through the creation of a
larger field of influence of the discharge and through the
acceleration of the ionized particles in the plasma toward the
higher density voltage conductor. The extension of the plasma
discharge can also be applied in other areas of industry, such as
the sterilization of food and any other area where dielectric
barrier discharges are used. This embodiment is similar in function
to that depicted in FIG. 13 except that the curved electrode 1302
can be replaced with a flat electrode which is parallel with
electrode 1301 and consists of multiple conductors of different
potential in order to augment the electric field strength to
increase the length the ionized particles travel. This also
increases the effectiveness of the plasma actuator in acting on a
fluid medium by widening the plasma actuators range of influence on
the fluid body.
[0098] FIG. 14 shows an exemplary embodiment of an actuator and
controller system 1400. As can be seen therein, in embodiments, the
system 1400 can include a solenoid actuator 1402 (which can be any
of the actuator embodiments and include any of the components
thereof shown and described in FIGS. 2A-13). The actuator 1402 is
on one more electrical circuits for communication with one or more
power sources 1404 (such as, e.g., variable power sources), where
closing and opening of the electrical circuits are respectively
controlled by one or more switches 1406. The system 1400 can
optionally include a position sensor(s) 1408 configured to sense or
identify a position of one or more plunger(s) in the actuator 1402.
Each of the switches 1406, the power sources 1404, and the position
sensor 1408 can be in communication with one or more computerized
controller apparatus 1410. The computerized controller apparatus
1412 can include, for example, a communication interface 1412, one
or more processors or microprocessors 1414 that comprise memory (or
data storage apparatus) 1416, and/or a graphical user interface
(GUI) 1418 configured to receive user input and/or display data to
a user. The memory 1416 can store one or more computer programs
therein including a plurality of computer-executable instructions
for operating or controlling the actuator 1402 to perform the
various operations and applications discussed above with reference
to FIGS. 2A-13 and elsewhere herein.
[0099] In exemplary embodiments, the foregoing processors and/or
microprocessors can include various types of digital processing
devices including, without limitation, digital signal processors
(DSPs), reduced instruction set computers (RISC), general-purpose
(CISC) processors, microprocessors, gate arrays (e.g., FPGAs),
PLDs, state machines, reconfigurable computer fabrics (RCFs), array
processors, secure microprocessors, and application-specific
integrated circuits (ASICs). Such digital processors may be
contained on a single unitary integrated circuit (IC) die or
distributed across multiple components. Further, in exemplary
embodiments, the foregoing memory and storage devices can include
various types of integrated circuit or other storage devices
adapted for storing digital data including, without limitation,
ROM, PROM, EEPROM, DRAM, SDRAM, DDR/2 SDRAM, EDO/FMS, RLDRAM, SRAM.
"flash" memory (e.g., NAND/NOR), 3D memory, and PSRAM. Furthermore,
in exemplary embodiments, the foregoing communication interface can
be a signal or data interface with a component or network
including, without limitation, those of the FireWire (e.g., FW400,
FW800, etc.), USB (e.g., USB 2.0, 3.0. OTG), Ethernet (e.g.,
10/100, 10/100/1000 (Gigabit Ethernet), 10-Gig-E, etc.), MoCA,
LTE/LTE-A, Wi-Fi (802.11), WiMAX (802.16), Z-wave, PAN (e.g.,
802.15)/Zigbee, Bluetooth, Bluetooth Low Energy (BLE) or power line
carrier (PLC) families.
[0100] Additional examples of the disclosed technology are
enumerated below.
[0101] 1. An improvement to the length of stroke of systems of
force production through the use of magnetic fields through the
introduction of non-linearity of the flux density along the length
of the coil and along the length of a rod containing permanent
magnets.
[0102] 2. A method of displacing the point of centralized force
within a coil or solenoid by changing the field density
distribution.
[0103] 3. An optimization of non-linear coil geometry for the
application of the acceleration of a moving object by creating
coils or the magnetic field of an apparatus in a non-linear
shape.
[0104] 4. A linear motion producing apparatus, which operates with
the capability of a longer stroke through the displacement of the
point at which the balance of magnetic forces is achieved on a
moving object in the system with an application in linear
actuators, linear motors, linear accelerators, mechanical
oscillators, etc.
[0105] 5. A method of tailoring the force profile in
electromagnetic systems of motion including to motors, actuators,
etc.
[0106] 6. A system with a plurality of coils of asymmetrically
oriented flux densities that are capable of individually biasing
the electric power so as to allow precise actuation of a moving
object. In this manner any desired direction, speed, or distance of
stroke of the linear actuator may be provided.
[0107] 7. A system comprising of variable magnetic density
permanent magnets where an electromagnet or another permanent
magnet is made to move along a relatively longer stroke.
[0108] 8. A system in which the tailoring of the force on an object
is attainable through the manipulation of field density over the
stroke of said object, which may be non-linear, giving rise to
non-linear acceleration profiles. These acceleration profiles and
magnetic density profiles may advantageously include the inverse
square curve, the hyperbolic curve, or a distribution that follows
that of the Brachistochrone curve. The most efficient curve for
force distribution is the curve that most closely represents that
of the natural permanent magnet, which is the curve made by the
inverse square law.
[0109] 9. A system in which the function of the increase in
magnetic field density of the coil system or the permanent magnets
can be tailored to an application or altered for maximum
efficiency.
[0110] 10. Furthermore, the function of the increase in magnetic or
electric field density of the coil system, permanent magnets, or
electric charges can be tailored to an application or altered for
maximum efficiency. The highest efficiency of operation would be
given by a field in the shape of the curve of the inverse square
law.
[0111] 11. A system in which the non-linearity of the forces in a
system of a linear or rotational actuator comprising of non-uniform
magnetic fields can be altered by the introduction of a source of
tension (a rubber band, for example).
[0112] 12. A system in which many additional systems of force can
be attached to the moving and stationary member(s) of a nonuniform
field distribution actuator using rigid or semi-rigid means.
[0113] 13. A system of movement, which can comprise a system of
nonuniform field distributions using no permanent magnets at all
when a plurality of electromagnetic coils are used.
[0114] 14. A system comprising of one or more coils, magnets,
electrostatic, or other sources of high electric potential with
asymmetrically distributed flux fields that can be incapsulated in
an air or watertight enclosure, without departing from the scope of
the disclosed technology.
[0115] 15. A system of non-linear flux density that can be made
without using standard circular coil windings, and motion can be
made to occur on any other object, which acts on or is acted upon
by a magnetic field.
[0116] 16. Without departing largely from the scope of the
disclosed technology, the electromagnetic coils and permanent
magnets can be replaced by electrostatic potentials with elements
comprised of increasing flux densities on one direction, which can
be acted upon by an object with an electrostatic charge or bias
including electrets and charged conductors.
[0117] 17. A system that possesses asymmetrically dense flux
fields, which can act in either attraction or repulsion in order to
provide movement or actuation.
[0118] 18. A system in which a linear actuator or linear motor may
have one moving part that travels nearly the full length of the
actuating coil, reducing the redundant space of a common solenoid
or voice coil, thereby offering the possibility to do away with
multiple moving parts.
[0119] 19. A system where multiple permanent magnets of the same
size and flux density may be used in an ordinary geometry
electromagnetic coil by altering the distance of the permanent
magnets to the coil in use over the axis of the object to be set in
motion.
[0120] 20. A linear actuator comprising: a plunger, one or more
first coil members circumscribing a central axis, wherein the one
or more first coil members are configured to produce a first
asymmetrical field distribution having a greater flux density at a
first end of the linear actuator, and one or more second coil
members circumscribing the central axis, wherein the one or more
second coil members are configured to produce a second asymmetrical
field distribution having a greater flux density at a second
opposing end of the linear actuator, wherein the one or more first
coil members and the one or more second coil members are further
configured such that the each of first asymmetrical flux density
and the second asymmetrical flux density is independently
controllable to cause motion of the plunger along the central axis
relative to the one or more first coil members and the one or more
second coil members.
[0121] 21. A linear actuator according to any of the examples
disclosed herein, wherein the one or more first coil members
comprises a first coil on a first circuit, the first coil
comprising two or more sections of first windings, each of the two
or more sections of first windings at least partially radially
overlapping with an adjacent section of first windings, the two or
more sections of first windings configured such that there is a
greater number of overlapping first windings distributed toward the
first end of the linear actuator relative to a center of the linear
actuator.
[0122] 22. A linear actuator according to any of the examples
disclosed herein, wherein the one or more second coil members
comprises a second coil on a second circuit, the second coil
comprising two or more sections of second windings, each of the two
or more sections of second windings at least partially radially
overlapping with an adjacent section of second windings, the two or
more sections of second windings configured such that there is a
greater number of overlapping second windings distributed toward
the second opposing end of the linear actuator relative to a center
of the linear actuator.
[0123] 23. A linear actuator according to any of the examples
disclosed herein, wherein the one or more first coil members
comprises a plurality of first coil members each on a separate
circuit, wherein each first coil member comprises a portion of
first windings that radially overlaps with an adjacent first coil
member, the plurality of first coil members configured such that
there is a greater number of overlapping first windings distributed
toward the first end of the linear actuator relative to a center of
the linear actuator.
[0124] 24. A linear actuator according to any of the examples
disclosed herein, wherein the one or more second coil members
comprises a plurality of second coil members each on a separate
circuit, wherein each second coil member comprises a portion of
second windings that radially overlaps with an adjacent second coil
member, the plurality of second coil members configured such that
there is a greater number of overlapping second windings
distributed toward the second opposing end of the linear actuator
relative to a center of the linear actuator.
[0125] 25. A linear actuator according to any of the examples
disclosed herein, wherein the one or more first coil members and
the one or more second coil members are further configured such
that the each of first asymmetrical flux density and the second
asymmetrical flux density are independently controllable to stop
motion of the plunger along the central axis relative to the one or
more first coil members and the one or more second coil
members.
[0126] 26. A linear actuator according to any of the examples
disclosed herein, further comprising a first variable power source
in communication with the one or more first coil members, and a
second variable power source in communication with the one or more
second coil members.
[0127] 27. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured for
communication with a controller, the controller in communication
with and configured to control power from a first variable power
source to the one or more first coil members for production of the
first asymmetrical field density and control power from a second
variable power source to the one or more second coil members for
production of the second asymmetrical field density.
[0128] 28. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured to be
controlled such that, when more power is applied to the one or more
first coil members relative to the one or more second coil members,
the first asymmetrical flux density acts on the plunger to result
in at least one of movement of the plunger toward the first end of
the linear actuator or retarding movement of the plunger toward the
second opposing end of the linear actuator.
[0129] 29. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured to be
controlled such that, controlling a ratio of flux density of the
first asymmetrical flux density relative to the second asymmetrical
flux density results in control of one or more of a speed of the
plunger moving along the central axis, a position of the plunger on
the central axis, a direction of movement of the plunger along the
central axis, or a stroke length of the plunger along the central
axis.
[0130] 30. A linear actuator comprising: one or more first coil
members circumscribing a central axis, and a plunger disposed at
least partially within the one or more first coil members, wherein
the one or more first coil members are configured to produce a
first asymmetrical field distribution having a first peak density
toward a first end of the linear actuator, and wherein the first
asymmetrical field distribution is configured to have an increased
maximum stroke length of the plunger along the central axis
relative to a coil having symmetrical field density and a same
length as the one or more first coil members.
[0131] 31. A linear actuator according to any of the examples
disclosed herein, wherein the one or more first coil members
comprises a plurality of first coil members each on a separate
circuit, wherein each first coil member comprises a portion of
first windings that radially overlaps with an adjacent first coil
member, the plurality of first coil members configured such that
there is a greater number of overlapping first windings distributed
toward the first end of the linear actuator.
[0132] 32. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured such
that a polarity of each of the one or more first coil members is
independently controllable relative to others of the one or more
first coil members.
[0133] 33. A linear actuator according to any of the examples
disclosed herein, further comprising one or more second coils
members circumscribing the central axis, the one or more second
coil members arranged to have a greater coil density at the second
opposing end of the linear actuator relative to a center of the
linear actuator, wherein the one or more second coil members are
configured to produce a second asymmetrical field distribution
having a second peak density toward the second opposing end of the
linear actuator.
[0134] 34. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured for
communication with a controller, the controller configured to
control a ratio of flux density between the first asymmetrical
field distribution and the second asymmetrical field distribution
to control one or more of a speed of the plunger moving along the
central axis, a position of the plunger on the central axis, a
direction of movement of the plunger along the central axis, or a
stroke length of the plunger along the central axis.
[0135] 35. A linear actuator comprising: a plunger; one or more
first coil members circumscribing a central axis and comprising a
greater number of overlapping windings at a first end of the linear
actuator relative to a center of the linear actuator, wherein the
one or more first coil members are configured to generate a first
asymmetrical field distribution having a greater flux density at
the first end of the linear actuator; a first variable power source
in communication with at least one of the one or more first coil
members; one or more second coil members circumscribing the central
axis and comprising a greater number of overlapping windings at a
second opposing end of the linear actuator relative to the center
of the liner actuator, wherein the one or more second coil members
are configured to generate a second asymmetrical field distribution
having a greater flux density at the second opposing end of the
linear actuator; and a second variable power source in
communication with at least one of the one or more first coil
members; wherein the one or more first coil members and the one or
more second coil members are further configured such that one or
more of a speed of the plunger moving along the central axis, a
position of the plunger on the central axis, a direction of
movement of the plunger along the central axis, or a stroke length
of the plunger along the central axis is controlled via a ratio of
flux density between the first asymmetrical field distribution and
the second asymmetrical field distribution.
[0136] 36. A linear actuator according to any of the examples
disclosed herein, wherein the linear actuator is configured for
communication with a controller, the controller in communication
with and configured to control power from the first variable power
source to the one or more first coil members for production of the
first asymmetrical field density and control power from the second
variable power source to the one or more second coil members for
production of the second asymmetrical field density.
[0137] 37. A linear actuator according to any of the examples
disclosed herein, wherein the plunger comprises two or more plunger
segments each connected to an adjacent plunger segment by a
connection member.
[0138] 38. A method of operating a linear actuator, the linear
actuator comprising a plunger, one or more first coil members
circumscribing a central axis and comprising a greater number of
overlapping windings at a first end of the linear actuator relative
to a center of the linear actuator, and one or more second coil
members circumscribing the central axis and comprising a greater
number of overlapping windings at a second opposing end of the
linear actuator relative to the center of the liner actuator, the
method comprising: controlling power from a first variable power
source to the one or more first coil members, the one or more first
coil members configured to generate a first asymmetrical field
distribution; and controlling power from a second variable power
source to the one or more second coil members, the one or more
second coil members configured to generate a second asymmetrical
field distribution; wherein the controlling of power from the first
variable power source and the controlling of power from the second
variable power source comprises generating a specified ratio of
flux density between the first asymmetrical flux density and the
second asymmetrical flux density, the specified ratio of flux
density configured to result in one or more of a specified speed of
the plunger moving along the central axis, a specified position of
the plunger on the central axis, a specified direction of movement
of the plunger along the central axis, or a specified stroke length
of the plunger along the central axis.
[0139] 39. A computerized controller configured for communication
with a linear actuator, the linear actuator comprising a plunger,
one or more first coil members circumscribing a central axis and
comprising a greater number of overlapping windings at a first end
of the linear actuator relative to a center of the linear actuator,
and one or more second coil members circumscribing the central axis
and comprising a greater number of overlapping windings at a second
opposing end of the linear actuator relative to the center of the
liner actuator, the one or more first coil members configured to
generate a first asymmetrical flux density, and the one or more
second coil members configured to generate a second asymmetrical
flux density, the computerized controller comprising: a
communication interface configured for communication with each of a
first variable power source for providing power to the one or more
first coil members and a second variable power source for providing
power to the one or more second coil members; one or more processor
apparatus; one or more storage apparatus in communication with the
one or more processor apparatus, the one or more storage apparatus
comprising non-transitory memory storing a plurality of
computer-readable instructions therein, the plurality of
computer-readable instructions configured to, when executed by the
one or more processor apparatus, cause the computerized controller
to: identify a specified ratio of flux density between the first
asymmetrical flux density and the second asymmetrical flux density;
control, based at least in part on the specified ratio of flux
density, power flow from the first variable power source to the one
or more first coil members; and control, based at least in part on
the specified ratio of flux density, power flow from the second
variable power source to the one or more second coil members;
wherein, when the control of the power flow from the first variable
power source and the control of the power flow from the second
variable power source comprises causing more power to be applied to
the one or more first coil members relative to the one or more
second coil members, the first asymmetrical flux density acts on
the plunger to result in at least one of movement of the plunger
toward the first end of the linear actuator or retarding of
movement of the plunger toward the second opposing end of the
linear actuator; and wherein, when the control of the power flow
from the first variable power source and the control of the power
flow from the second variable power source comprises causing more
power to be applied to the one or more second coil members relative
to the one or more first coil members, the second asymmetrical flux
density acts on the plunger to result in at least one of movement
of the plunger toward the second opposing end of the linear
actuator or retarding of movement of the plunger toward the first
end of the linear actuator.
[0140] Any feature(s) of any example(s) disclosed herein can be
combined with or isolated from any feature(s) of any example(s)
disclosed herein, unless otherwise stated. Further, in view of the
many possible embodiments to which the principles of the disclosure
may be applied, it should be recognized that the illustrated
embodiments are only examples and should not be taken as limiting
the scope of the disclosed subject matter or the claims.
[0141] In view of the many possible embodiments to which the
principles of the disclosed invention may be applied, it should be
recognized that the illustrated embodiments are only preferred
examples of the invention and should not be taken as limiting the
scope of the invention. Rather, the scope of the invention is
defined by the following claims. We therefore claim as our
invention all that comes within the scope and spirit of these
claims.
* * * * *